A squat machine is a piece of fitness equipment designed to guide your movement and isolate your lower body. Common types include hack squat machines (angled backrests that guide movement), V-squat machines (spinal-friendly alternatives), and sissy squat machines (which isolate the quads for deep bodyweight leans).Using these machines allows you to train your legs heavily while minimizing the balancing demands and lower-back stress associated with traditional barbell squats.